Attrition-mill plate.



E. P. ALSTED.

ATTRITION MILL PLATE.

APPLICATION FILED DEC. 16. 19l2. 1,144,089;

Patented June 22, 1915. Z 2 SHEETS-SHEET l. 54/ '2 E. P. ALSTED.

ATTR ITION MILL PLATE. APPLICATION FILED DEC. 16, 1912.

1,144,089. Patented June 22, 1915.

' 2 SHEETS-SHEET 2.

EDWARD R'ALSTED, OF TBUESDELL, WISCONSIN.

ATTRITION-MILL PLATE.

Specification of Letters Patent.

Patented June 22, 1915.

Application filed December 16, 1912. Serial No. 736,949.

T aZZ whom it may concern:

Be it known that I, EDWARD P. ALSTED, a citizen of the United States,and resident of Truesdell, in the county of Kenosha and State ofWisconsin, have invented new and useful Improvements in Attrition-Mil]Plates, of which the following is a descrip tion, reference being had tothe accompanying drawings, which are a part of this speci' fication.

This invention relates to improvements in attrition mill plates betweenthe opposing faces of which the material to be ground is introduced.

One of the objects of this invention is to provide grinding disk platesfor attrition mills in which the material fed between the plates fromthe inner peripheries thereof is evenly distributed throughout theentire grinding surfaces of the plates thereby preventing uneven wear onthe plates and forming a more efficient reducing surface.

A further object of the invention is to provide grinding disk plates forattrition mills with ribs of peculiar configuration which are shaped todistribute the material evenly throughout the entire grinding faces ofthe plates to prevent uneven wear of said plates.

A further object of the invention is to provide grinding plates forattrition mills in which the pockets of the plates are so positionedwithrelation to pockets of opposite plates as to overlap each other andpermit material to pass radially from one series of pockets to another.

' With the above and other objects in view, the invention consists ofthe improved grinding disk plates and their parts and combinations asset forth in the claims, and

all equivalents thereof.

In the accompanying drawings in which the same reference charactersindicate the same parts in all of the views:

Figure 1 is a face view of a fragment of a grinding disk provided withthe improved grinding face. Fig. 2 is a transverse sectional viewthereof taken on line 22 of Fig. 1; Fig. 3 is a face view on a reducedscale of the completed disk; Fig. 4 is a diagrammatic view of one ofthe'ribs of each opposing disk showing the line of engagement of thematerial reducing edges and the overlapping of the pockets of oppositeplates, one of the ribs being indicated by dotted lines. Fig. 5 is aface view of a fragment of a modified form of disk; Fig. 6 is atransverse sectional View thereof taken on line 66 of Fig. 4; Fig. 7 isa face view of a fragment of another form of disk; and Fig. 8 is atransverse sectional view taken on line 8-8 of Fig. 7.

Referring to the drawings the numeral 10 indicates one of a plurality ofsegmental grinding plates which are adapted to be fastened to theopposing heads or disks of an attrition mill by means of screws 11 eX-tending through openings 12 provided in said segments and threaded tothe disks to form a complete grinding face for said disks. The segmentalplates are provided with long, short and intermediate length radial ribs13, l-t and 15 respectively which are spaced equi-distantlycircumferentially on the face of the plate.

The outer ends of the ribs are joined to; gether by an outer concentricrib l6 and the medial portions of the ribs are joined together by atransverse biangular rib 17 which extends approximately heXagonally inform around the face of the assembled plates. Portions of the sides ofthe hexagonal form are omitted or broken away to provide outlet openings18 to permit the material to pass freely toward the outer portions ofthe ribs. These openings are guarded by short ribs 19 which overlap theend portions of the sides and are spaced radially outwardly a shortdistance beyond the said sides. The radial and other ribs form pockets20 of various lengths into which the material is fed and is engaged bythe edges 21 of the ribs forming said pockets and reduced thereby.

The inner concentric edges 22 of the plates are beveled or rounded of tomore freely admit the material into the pockets and the spaces betweenthe radial ribs.

The faces of the ribs at points indicated by the numeral 23 andapproximately midway between the inner and outer peripheries of theplates 10 are of less width than the other portions and from thesepoints the rib faces taper radially toward their opposite ends to agreater width to provide a shearing cut between the ribs of oppositeplates, so that the line of engagement of the shearing cut will travelfrom points near the outer and inner peripheries of the plates towardthe medial portions thereof. This construction serves to distribute thewear of cutting along the edges of the entire length of the ribs insteadof at the outer ends of the ribs as in grinding disks of ordinaryconstruction. 7

As the corner portions 24 of the transverse or biangular extending ribs17 extend radially beyond the portions forming the.

sides of the hexagonal form, the opposite rotation of the disk willcause the said corners to overlap the opposite side portions of I thematerial between the plates until it is reduced to the degree offineness regulated by the spacing of the disks apart.

In the modified form shown in Figs. 5 and 6 radial ribs 25 are providedwhich are similar to the radial ribs of the principal form and thetransverse ribs 26 are of biangular formation and are spaced a greaterdistance from similar adjacent ribs than in the other form. A series ofshort ribs 27 guard the spaces between the biangular ribs.

This form of plate is adapted to reduce the material in substantiallythe same manner as before described and the same description will apply.

In the modified form shown in Figs. 7

I and 8 the biangular rib 28 of each plate joins with the ribs ofadjacent plates and forms a continuous rib of approximately star shapeand the short ribs 29 while of greater length than theribs of the otherforms are similarly positioned with relation to the angular ortransverse ribs and are adapted to perform the same function.

This last mentioned modification is provided with ribs on opposite sidesof the plate so that when one side is worn the other side may be used. 7

Both sides of all of the ribs are of similar form to provide for doublewear by rotating in the opposite direction when the edges extending inone direction are worn.

From the foregoing description it will be seen that the plates areadapted to spread the material over the entire working surface and alsothat the shearing engagement is extended along the entire length of theribs thus eliminating wear at one point on each rib.

What I claim as my invention is:

1. Attrition mill plates, comprising oppositely rotatable platesprovided with material reducing radial ribs of varying lengths,

the material engaging edges of ribs of opposite plates-diverging towardthe axis of the plates when in engagement with each other for a portionof their lengths to advance the line of material engagement in adirection toward the axis of rotation, and transverse ribs extendinginapproximately straight short broken lines circumferentially around themedial portions of the faces of the plates, said brokenlines oftransverse ribs forming outlet openings permitting the reduced materialto work outwardly.

2. Attrition mill plates, comprising oppo- 'sitely rotatable platesprovided with material reducing radial ribs of varying lengths and withtransverse ribs, the medial face portions of the radial ribs being ofless width thantheir opposite end portions to advance-the line ofmaterial engagement to ward said medial face portions, the transverseribs extending in "approximately straight short broken lines which havea shearing engagement with like ribs of op- I posite plates, said brokenlines of transverse ribs forming outlet openings permitting the reducedmaterial to work outwardly. V 1

3. A grinding plate for attrition mills, comprising a segmental plateprovided with radial ribs of varying lengths, other ribs extendingtransversely across the radial ribs and also extending approximately instraight short broken lines hexagonally around the face of the plate andshort transverse guard ribs overlapping the broken portions of thebroken ribs, said broken lines of transverse ribs forming outletopenings permitting the reduced material to work outwardly.

4. A grinding plate for attrition mills provided with material reducingradial ribs of varying lengths and with short angular ribs which extendacross the radial ribs at angles other than at right angles, said shortribs forming outlet openings permitting the reduced material to workoutwardly.

5. A grinding plate for attrition mills, comprising segmental platesprovided with material reducing radial ribs of varying lengths which areof less width medially than at their outer ends, and short biangularribs extending across the radial ribs, said short ribs forming outletopenings permitting the reduced material .to "work out-' wardly.

6. A grinding plate for attrition mills,

comprising segmental plates provided with ribs, said outlet openingspermitting the material reducing radial ribs of varying reduced materialto work outwardly. 1o lengths, biangular ribs extending across the Intestimony whereof, I affix my signaradial ribs, the ends of saidbiangular ribs ture, in presence of two witnesses.

being spaced from the ends of similar ad- EDWARD P. ALSTED. jacent ribsto form outlet openings and other Witnesses:

ribs extending across said openings and CHARLES E. TURNOCK,

spaced outwardly from the said biangular LAURA O. BALDWIN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents.

Washington, D. G. V

